The Giants absolutely cannot let Cabrera walk this winter. A five-year contract extension as soon as the season ends would make a lot of sense for both sides.

Cabrera has two things working strongly in his favor, and two things working against him as he approaches free agency.

On the positive side, he's only 27 years old, which is young for a free agent. Even better, the last two seasons have been the best of his career, so he heads into free agency with momentum.

On the negative side, Cabrera only has two good seasons on his resume during his seven-year big league career. The first four seasons of his career were mediocre, the fifth was so bad that he was designated for assignment by Atlanta and the last two have been excellent.

The other thing working against him is that although the free-agent market is thin overall, the outfield market is fairly deep with Cabrera, Josh Hamilton, Shane Victorino, Angel Pagan, B.J. Upton, Michael Bourn and Torii Hunter all hitting the market this winter.

Cabrera was very good for Kansas City last year, and he's been an MVP candidate for the Giants so far this season. However, if we take a close look at the numbers, his 2011 performance is likely closer to his true talent level:

Cabrera has become slightly more patient and powerful this season. The increase in power is surprising given that he has hit more ground balls and line drives in place of fly balls this season.

The big jump in Cabrera's numbers has been the six-percent bump in BABIP, which is likely not sustainable since it is accompanied by a less than a three-percent jump in line drives.

Even if Cabrera is more of a .300-.320 type of hitter than the .350-.360 he's been batting this season, he's still a really good player that deserves a big contract. He isn't good enough defensively to play center, but he has a huge arm and solid range in a corner. He's also an excellent asset on the bases with very good speed.

Given that Cabrera is only 27 years old right now, a five-year contract extension would only take him through his age 32 season. With his combination of speed, power, range, arm strength, youth and contact ability, a five-year contract makes a lot of sense.

When you factor in Cabrera's inconsistent track record, inability to play center field, lack of home run power and that his outstanding 2012 campaign is heavily influenced by some luck on balls in play, his earning power is reduced a bit. Most players tend to lose some value as they get deeper into their contracts as well.

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Considering all of that, Cabrera should probably be worth $12-16 million per season. That makes a five-year contract worth between $60-80 million a very good estimate for what Cabrera should get on the open market.

Outfielders do tend to be riskier investments than infielders, as the Giants learned when they gave Aaron Rowand a 5-year, $60 million contract after his outstanding 2007 season in Philadelphia. Rowand is currently collecting the final $12 million of the Giants' investment on his couch, as he was designated for assignment before the fourth season of the deal even ended.

Like Cabrera, Rowand had an inconsistent track record with only two good seasons on his resume. Rowand could also play center field, while Cabrera is limited to a corner. However, Cabrera is two years younger than Rowand was when he hit free agency. Cabrera is also a stronger overall hitter with superior contact rates, and he's a better athlete with more speed and arm strength.

All contracts are fraught with risk, but Cabrera is a player the Giants should take a gamble on. Not all contracts work out, but that doesn't mean you shouldn't play the market.

Melky Cabrera has turned himself into an outstanding baseball player after a slow start to his big league career. He has a legitimate chance to win the NL MVP Award this season, and though he may not be an MVP-caliber player going forward, he's a player the Giants need to invest in.